S(S#，SNAME，SEX，AGE)，C(C#，CNAME，TEACHER)，SC(S#，C#，GRADE)。To find the name of all "female" students taking a "COMPUTER" course involves
A. S
B. SC，C
C. S，SC
D. S，C，SC
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In the SQL language, the command to delete all the data in a table but keep the table structure is ()
A. DELETE
B. DROP
CLEAR
D. REMORE
A function used to find the date of a system is ( )
A. YEAR()
B. GETDATE()
COUNT()
D. SUM()
which one is wrong( )。
A. select right('hello',3)return value=hel
B. select ltrim(rtrim(' hello '))return value=hello (without spaces)
C. select replace('hello','e','o') return value=hollo
D. select len('hello') return value=5
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